Fachie will be going for his second gold medal, following success in the 1km time trial, while Kappes will be looking to make up for his disqualification in the same event.
In the first heat Kappes and his pilot Craig Maclean went through comfortably, winning the first two races.
They were too powerful and tactically aware for their Japanese opponents, particularly in the second race, when they powered off the penultimate bend to blow their rivals away.
In the other semi-final, Fachie and Barney Storey were happy to let the Spanish team lead in the first race, before coming back strongly to win.
The second race was slightly different, with Fachie and Storey leading early on and maintaining the gap to go through the the final.
The final will take place later this afternoon.